Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number PS2 3 4 found under Bearing Unit Ball by Altra Holdings Inc. The National Stock Number assigned to this part is 3130013450668, and the Federal Supply Class is 3130 Bearings Mounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like PS2 3 4.